Chemical process for retaining cutting edges



Patented Jan. 26, 1954 CHEMICAL PROCESS FOR RETAINING CUTTING EDGES Clarence Frederick Young, Great Barrington, -Mass.

No Drawing. Application June 24, 1950, Serial No. 170,263

6 Claims.

This invention relates to a method of prolonging the useful life of sharp cutting edges or blades and more particularly to prolonging the useful life of razor blades.

Sharp razor blades and other sharp edged tools, such as knives, saws, axes, and the like, after even a single use, become less sharp or dull, so that on re-use the cutting edge is not as effective as in the case of their first or initial use. These blades may be sharpened mechanically; but such processes are tedious and time-consuming and hardly Worth the effort in the case of cheap razor blades.

I have invented an inexpensive method of prolonging the useful life of metallic steel or other alloy blades, dulled or rendered less sharp through useage, which comprises treating or placing the used blade in contact with or in the presence of a dissimilar metal or alloy in a chemical solution for a plurality of hours. Intermittent use of the blade followed by immersion in my chemical solution as above described will keep a blade sharp for prolonged periods of time.

This invention will hereinafter bedescribed in detail with reference to prolonging the life of a sharp edge of a steel razor blade locked in place in a metal, for example, brass, razor blade holder; a combination commonly used for shaving, and generally known as a safety razor blade combination.

By Way of an example of carrying out my invention, I place the used safety blade combination, after having first washed it free from soap and particles of whiskers, in a glass container in an aqueous solution of a soluble salt, for example, a

soluble dichromate, or more particularly potassium dichromate. The strength of the aqueous solution may be varied from a dilute solution or" about .0001 per cent or even less to a concentrated solution of 50 per cent and more. The concentration of potassium dichromate I may use, may be varied considerably throughout a wide range. The potassium dichromate is effective in preventing rust formation and also in retaining the cutting edge of the blade.

The theory of this chemical prolonging the useful life of a cutting edge is not well understood. It may be that electrochemical phenomena are present, especially since another metal, for ex ample, brass, appears to be necessary to bring about effective results. Also, since brass is an alloy of the elements copper and zinc, it may be that one of these elements alone, or some other equivalent metal or element will sufilce.

The duration of contact in hours, between the potassium dichromate solution and the safety 2 razor blade combination, also may vary considerably. Thus a duration of a few hours produces noticeable results, but a duration of several hours, for example 10 to 20 hours, is recommended for best results.

I have found that repeated treatments in dichromate solution, up to 30 times and more maintained as sharp an edge as when the razor blade was initially used in its purchased state. Other chemicals equivalent to potassium dichromate may be used, in the preparation of my solutions for example, sodium dichromate, or other equivalents. Also water-soluble organic liquids, for example, alcohol may be substituted in part for Water in the preparation of my chemical solutions.

As stated previously I do not know the precise theory or explanation for this phenomenon of retaining a sharp cutting edge; however, theory is not controlling, since it suhices that I have discovered this process and herein fully describe it.

The scope of this invention is therefore not to be limited by the precise example or examples herein shown, since other chemical equivalents and other equivalent conditions of procedure may be substituted in this invention and these are intended to be covered by the following claims.

I claim:

1. Process for retaining thecutting edge of a steel blade in contact with brass metal consisting of treating said steel blade for a plurality of hours in contact with an aqueous solution consisting of a soluble dichromate.

2. Process for retaining the cutting edge of a steel blade in contact with brass metal consisting of treating said blade for a plurality of hours in contact with an aqueous solution consisting of sodium dichromate.

3. Process for retaining the cutting edge of a steel blade in contact with brass metal consisting of treating said blade for a plurality of hours in contact with an aqueous solution consisting of potassium dichromate.

4. Process for retaining the cutting edge of a steel razor blade in contact with brass metal consisting of treating said blade for a plurality of hours in contact with an aqueous solution consisting of sodium dichromate at room temperature.

5. Process for prolonging the life of a sharp edge of a razor blade consisting of immersing said blade in the presence of a brass metal in a solu' tion consisting of soluble dichromate having a solution strength of about .0001% to about 50%.

6. Process for prolonging the life of a sharp edge of a metallic blade subjected to intermittent use, consisting of treating said blade after each use by immersing it for a plurality of hours in an aqueous solution consisting of a soluble dichromate in contact with brass, said solution having a strength of about .01% to about 25% dichromate.

C. FREDERICK YOUNG.

References Cited in the file of this patent UNITED STATES PATENTS Number 4 Number Name Date 1,777,914 Davis Oct. 7, 1930 2,074,833 Fash Mar. 23, 1937 FOREIGN PATENTS Number Country Date 529,604 France Sept. 13, 1921 10 by Evans, 2nd edition (1946), page 557. 

1. PROCESS FOR RETAINING THE CUTTING EDGE OF A STEEL BLADE IN CONTACT WITH BRASS METAL CONSISTING OF TREATING SAID STEEL BLADE FOR A PLURALITY OF HOURS IN CONTACT WITH AN AQUEOUS SOLUTION COSISTING OF A SOLUBLE DICHROMATE. 